Work-locating pin for jigs



July 22, 1930. c. E. PIOCH WORK LOCATING PIN FORJIGS Filed June i926 g-wuwtoc Car/ 206% Patented July 22, 1930 v i UNITED stars-s sarnlnrorrics CARL E. PIOCII OF DETROIT, MICHIGAN, ASSIGNOR F oNE HALlF TO ALAN H. PEARSON,

. OF DETROIT, MICHIGAN WORK-LOCATING PIN FOR J'IGS Application filed June 9, 1926. Serial No. 114,764.

This invention relates to a device for use injured and which will have the necessary acwhere great accuracy is required in locating curacy and rigidity. A further object is to work during machining. operations or for provide certain other new and useful featemporarily holding one part, member or tures, all as hereinafter more fully set forth.

5 device relative to another while certain oper- 1th the above and'other ends in view, the ations are performed or work done, the the invention consists in the matters hereinafter Vice relating more specifically to improveset forth and more particularly pointed out ments in so called locating pins. in the appended claim, reference being had Locating devices of this character usually to the accompanying drawing in which 1 comprise an accurately formed stud or pin Figure 1 is a View showing the applicaea rigidly and permanently set within one memtlon of a devlce embodyingthe invention, to

er or part to engage an opening within the a fixture employed in connection with a borother member or part and accurately align 111g machine, as illustrative of one use to or hold the parts in the desired relation while which the invention maybe put;

certain operations are being performed or Fig. 2 is a detail view of the device show- 6 work done and so that the parts or members mg the detachable pin or stud thereof in clemay be readily separated and one part reation and in place within a socket member moved from the other when the operation is whlch is shown in section and in place within completed, the locating device remaining in an opening in a partor member in connection position on one part or member to again align with which the locator is adapted to be used; 7 the members during succeeding operations. F 1g. 3 1s a perspective view of the detach- This repeated engagement and disengageable pin or stud; ment of the locating device soon causes wear Fig. 4 is a similar View of the socket memwhich affects its accuracy and injury to the her;

locator is imminent at all times,particularly Fig. 5 is a sectional detail illustrative of a 755 where the re novg ble part, or 11153111 09 heavy IHOdifi Cfi-tlOl'l Of the application Of the lOCZltOl and cumbersome, and therefore it has been tOlftlPfifli or member in conjunction with found that frequent replacement of such den which it is adapted to be used; and vices is necessary. 7 Fig. 6 is a View showing a slightly modified In the usual construction, as the locator is form of stud or pin.

rigidly and permanently fixed within an As an illustration of one use to which the opening in the member or part by which it is devices embodying the present invention may carried, considerable time and skill. is re be put, a fixture 1 of suitable formifor appliquired to make such replacement and during cation to the table of a boring machine, not this time the parts or members cannot be used. Shown, is provided with vertical bores or Where such locators are used in connection openings accurately located relative to the with'fixtures for properly locating work upon axis of a boring tool 2 of the machine, and

a metal working machine, it is necessary to relative to accurately located holes in the remove the fixture from the machine in order Work, which work illustrated, is a cast- 40 to make the repair, with consequent loss in block for an internal combustion'engine, said time and production and in those cases where block comprising acylinder portion 3 to be the locating pin is broken off, it is often necesbored by the tool2 and acrank case portion 4' sary to bore out the remaining portion of the. having a base flange- 5 provided with bolt pin, and reform the hole to receive a newpim holes 6 which are utilized to receive locating thus causing a further loss and in some cases pins 'on the fixture 1 and accurately position necessitating the making of an entirely new the cylinder 3 relative to the tool2 of the bor- Xture. I ing machine. With locating devices properly An object of the present invention is to proset in l the fixture 1 and the fixture properly vide a locator which may be quickly and locatedrelative-to the axis of the boring tool easily removed and replaced when worn or 2, cylinders may be accurately bored, one

after another, by simply setting the work in place upon the fixture with the locating pins engaged in the holes in the flange of the crank case, but such pins must be accurately set, must fit such holes, and this accuracy must be maintained.

'1 he usual practice is to simply secure plain locating pins within openings in the fixture, but to obviate the difficulty arising from the removal and replacement of such pins, a locator of the character shown is provided, such locator comprising a hardened bushing 10 to accurately fit an opening or bore 11 in the fixture or other part or member and be permanently set therein, said bushing having a lateral flange 12 at its upper end to seat} upon the upper surface of the fixture and being bored axially to receive the detachable pin member which is indicated as a whole by the numeral 13. T his member 13 has a cylindrical shank portion 14: to tit within the bore of the bushing and the lower end 15 of? the pin is reduced in diameter and externally screwthreaded to engage the reduced and screwthreaded lower end of the bore. Adjacentthe upper end of the shank 14:, the pin is formed with a hexagonal head or flange 16 to seat upon the upper end 01" the bushing and to form a wrench hold by means of which the pin member may be screwed into the bushing member. The pin or pilot proper. or that portion 17 which is adapted to enter and fit within a hole in the work, is formed integral with and axially of the head 16, ant is accurately formed and rounded at its upper end to fit the hole in the work and to enter readily therein, the angle of juncture of the pilot 1? with the head 16 being formed with a fillet 18 in those cases where a rightanglc juncture is not necessary as illustrated in Fig. 1 or a slight groove 19, as shown in Fig. 6, may be provided at this line of juncture so that the part, member or work engaged by the pilot may rest accurately upon the upper face of the head 16 which will thus form an accurate bearing for the work. A seat or bearing for the work, other than the head 6 may be provided by enlarging the upper end of the opening in the fixture 1 as shown in Fig. 5 at 20, the recess thus formed Jeing of greater depth than the height of the head 16 so that the work will rest upon the upper surface of the fixture with the accurately formed cylindrical portion only of the pilot projectingupwardly beyond said surface to enter the hole in the work. in which case the fillet 18 may be employed and the pilot 17 strengthened thereby.

By providing a locating pin which may be readily removed by means of a wrench, whenever the pin or pilot becomes worn or injured, it may be very quickly removed by a workman of ordinary skill and another pin or-pilot screwed into place Without the necessity tor removing the fixture from the'boring or other machine, and by providing the hardened bushing 10 for the pilot, the pilot is firmly and accurately held and injury to the opening in the fixture incident to the removal of the pilot is obviated and greater and permanent accuracy secured.

Changes in the size, proportion, construction and arrangement of the parts of the locator to suit its application to the work and place of installation are contemplated, as well as its application to all uses to which it is adaptable, and I do not therefore limit myself to the particular construction shown and described, except where clearly set forth in the appended claim.

Having thus fully described my invention, what I claim is A device of the character described including'a bushing adapted to be fitted accurately into a stationary part of a machine, and a centering pin having a smooth wall adapted to be fitted accurately into said bushing and a threaded end adapted to screw into said bushing, said pin being formed to present a smooth unbroken surface adapted to enter the work, and having an enlargement on which the work may rest, said enlargement being adapted to rest on said bushing.

In testimony whereof I afiix my signature.

CARL E. PIOCH. 

